test-metrics-server.ts

#!/usr/bin/env bun

/**
 * Metrics Server Integration Test
 * Tests Prometheus metrics endpoint
 */

import { createDefaultMetricsServer } from './src/monitoring/metrics-server';
import { metrics, recordCommandExecuted, recordScriptExecuted } from './src/monitoring/metrics';

console.log('🧪 Metrics Server Integration Test');
console.log('━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━\\n');

// Test 1: Start Server
console.log('📝 Test 1: Start Metrics Server');
const server = createDefaultMetricsServer();
await server.start();
console.log('✅ Server started successfully\n');

// Wait a moment for server to be ready
await new Promise(resolve => setTimeout(resolve, 100));

// Test 2: Health Check Endpoint
console.log('📝 Test 2: Health Check Endpoint');
try {
  const response = await fetch('http://127.0.0.1:9090/health');
  if (!response.ok) {
    throw new Error(`Health check failed: ${response.status}`);
  }

  const data = await response.json();
  if (data.status !== 'healthy') {
    throw new Error('Health status not healthy');
  }

  console.log('✅ Health check endpoint works');
  console.log(`   Status: ${data.status}`);
} catch (error) {
  console.error('❌ Health check failed:', error);
  await server.stop();
  process.exit(1);
}
console.log();

// Test 3: Metrics Endpoint - Empty
console.log('📝 Test 3: Metrics Endpoint - Empty State');
try {
  metrics.reset();

  const response = await fetch('http://127.0.0.1:9090/metrics');
  if (!response.ok) {
    throw new Error(`Metrics fetch failed: ${response.status}`);
  }

  const contentType = response.headers.get('Content-Type');
  if (!contentType?.includes('text/plain')) {
    throw new Error(`Wrong content type: ${contentType}`);
  }

  const body = await response.text();

  // Should have uptime metric
  if (!body.includes('bot_uptime_seconds')) {
    throw new Error('Missing uptime metric');
  }

  console.log('✅ Metrics endpoint returns Prometheus format');
  console.log(`   Content-Type: ${contentType}`);
} catch (error) {
  console.error('❌ Metrics endpoint test failed:', error);
  await server.stop();
  process.exit(1);
}
console.log();

// Test 4: Metrics Endpoint - With Data
console.log('📝 Test 4: Metrics Endpoint - With Data');
try {
  metrics.reset();

  // Record some metrics
  recordCommandExecuted('deploy', true);
  recordCommandExecuted('deploy', false);
  recordCommandExecuted('status', true);
  recordScriptExecuted('backup', true, 2500);
  recordScriptExecuted('backup', true, 2800);
  recordScriptExecuted('backup', false, 5000);

  const response = await fetch('http://127.0.0.1:9090/metrics');
  const body = await response.text();

  // Check for command metrics
  if (!body.includes('bot_commands_total')) {
    throw new Error('Missing commands counter');
  }

  if (!body.includes('command="deploy"')) {
    throw new Error('Missing command labels');
  }

  if (!body.includes('success="true"')) {
    throw new Error('Missing success label');
  }

  // Check for script metrics
  if (!body.includes('bot_script_executions_total')) {
    throw new Error('Missing script executions counter');
  }

  if (!body.includes('bot_script_duration_ms')) {
    throw new Error('Missing script duration histogram');
  }

  if (!body.includes('script="backup"')) {
    throw new Error('Missing script label');
  }

  // Check histogram format
  if (!body.includes('bot_script_duration_ms_count')) {
    throw new Error('Missing histogram count');
  }

  if (!body.includes('bot_script_duration_ms_sum')) {
    throw new Error('Missing histogram sum');
  }

  if (!body.includes('quantile="0.5"')) {
    throw new Error('Missing histogram quantiles');
  }

  console.log('✅ Metrics endpoint exposes recorded data');
  console.log('   ✓ Command counters');
  console.log('   ✓ Script execution counters');
  console.log('   ✓ Script duration histogram');
  console.log('   ✓ Labels and quantiles');
} catch (error) {
  console.error('❌ Metrics with data test failed:', error);
  await server.stop();
  process.exit(1);
}
console.log();

// Test 5: Prometheus Format Validation
console.log('📝 Test 5: Prometheus Format Validation');
try {
  const response = await fetch('http://127.0.0.1:9090/metrics');
  const body = await response.text();

  // Check format: # HELP, # TYPE, metric lines
  const lines = body.split('\n').filter(l => l.trim());

  let hasHelp = false;
  let hasType = false;
  let hasMetric = false;

  for (const line of lines) {
    if (line.startsWith('# HELP')) hasHelp = true;
    if (line.startsWith('# TYPE')) hasType = true;
    if (/^[a-z_]+(\{[^}]+\})?\s+\d+/.test(line)) hasMetric = true;
  }

  if (!hasHelp) throw new Error('Missing # HELP lines');
  if (!hasType) throw new Error('Missing # TYPE lines');
  if (!hasMetric) throw new Error('Missing metric value lines');

  console.log('✅ Prometheus format valid');
  console.log(`   Total lines: ${lines.length}`);
  console.log(`   Metric groups: ${lines.filter(l => l.startsWith('# HELP')).length}`);
} catch (error) {
  console.error('❌ Format validation failed:', error);
  await server.stop();
  process.exit(1);
}
console.log();

// Test 6: 404 for Unknown Paths
console.log('📝 Test 6: 404 for Unknown Paths');
try {
  const response = await fetch('http://127.0.0.1:9090/unknown');
  if (response.status !== 404) {
    throw new Error(`Expected 404, got ${response.status}`);
  }

  console.log('✅ Unknown paths return 404');
} catch (error) {
  console.error('❌ 404 test failed:', error);
  await server.stop();
  process.exit(1);
}
console.log();

// Test 7: Sample Prometheus Scrape
console.log('📝 Test 7: Sample Prometheus Scrape Output');
try {
  const response = await fetch('http://127.0.0.1:9090/metrics');
  const body = await response.text();

  console.log('✅ Sample output (first 20 lines):');
  const lines = body.split('\n').slice(0, 20);
  for (const line of lines) {
    if (line.trim()) {
      console.log(`   ${line}`);
    }
  }
} catch (error) {
  console.error('❌ Sample output failed:', error);
}
console.log();

// Cleanup
console.log('📝 Cleanup: Stopping Server');
await server.stop();
console.log('✅ Server stopped\n');

// Summary
console.log('━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━');
console.log('✅ All metrics server tests passed!\\n');
console.log('📋 Summary:');
console.log('   - Metrics server starts and stops cleanly');
console.log('   - Health check endpoint works');
console.log('   - Metrics endpoint exposes Prometheus format');
console.log('   - Recorded metrics appear correctly');
console.log('   - Format validation passes');
console.log('');
console.log('💡 To run standalone metrics server:');
console.log('   bun src/monitoring/metrics-server.ts');
console.log('');
console.log('💡 To scrape metrics:');
console.log('   curl http://127.0.0.1:9090/metrics');
console.log('');